The Florida cottonmouth (Agkistrodon conanti) is a species of venomous snake, a pit viper in the subfamily Crotalinae of the family Viperidae.

The species is endemic to the United States, where it occurs in southern Georgia and the Florida peninsula in nearly every type of wetlands in the region, including brackish water and offshore islands.

[3]: 215-225 p. [4]: 249-274 p. [2]: 193-215 p. [5]: 437-438 p. [6] In the original description, Howard K. Gloyd wrote it was "named in honor of a friend and colleague, Roger Conant, Director of the Philadelphia Zoological Garden, whose professional achievements and dynamic promotion of the study of herpetology for amateurs merit highest commendation.

The holotype is a young adult male in the United States National Museum (USNM 165962), and the type locality is "at the edge of Rochelle-Cross Creek Road, about 7 miles southeast of Gainesville, Alachua County, Florida" .

[7]: 226 p.  Agkistrodon conanti was elevated to a full species in 2015 based on molecular data, phylogenetic evidence, and distinct ecological niches.

Allen and Swindell (1948) reported one male specimen from Marion County, Florida that measured 1,829 mm (72 inches) in total length and weighed 4.6 kg (10 pounds).

[3] The color pattern is very similar to that of A. piscivorus, apart from head markings that are plainly visible even in older darker specimens of A. conanti: with dark postocular stripes that are bordered above and below by narrow light lines.

[3]: 55 p. [4]: 250 p. Agkistrodon conanti is found in the southeast of the United States, throughout the Florida peninsula, including many barrier islands and keys, and into southern Georgia.

[3]: 208-209 p. [4]: 271 p. [16]: 403 p.  In one study ecological niche models predicted hybridization might occur from North Carolina to the southern coastal plains in southeastern Louisiana,[12]: 516 p.  however molecular data (DNA) from the same study indicated samples from individuals from the Savannah, Georgia area northward, as well as from areas north and west of Mobile Bay, Alabama were A. piscivorus (with the exception of a single hybrid from southern Mississippi).

Duellman and Schwartz (1958) described the species as inhabiting aquatic environments, cypress flats and wet prairies, but not pine forests, scrub or hammocks.